1. Field of the Invention
An inflator, which feeds gas into an airbag to inflate it, has a squib. To supply electric energy to this squib, a female connector is connected to a pair of pins of the squib. The present invention relates to a shunt, which short-circuits the pair of pins of the squib until the female connector is connected to the pair of pins.
2. Related Art
A shunt is known, which is fitted into a cylindrical socket being concavely formed in an external face of a housing of an inflator and short-circuits a pair of pins of a squib, said pair of pins rising at the center of the socket from the bottom up to the opening. For example, Japanese Patent unexamined publication gazette Heisei 6-208867 discloses a shunt that is called a short-circuit insert. This shunt has a short-circuit clip and uses this short-circuit clip to short-circuit a pair of pins of a squib so as to prevent the squib from false actuation. After an inflator is fitted into a vehicle, when a female connector is fitted into the socket, the female connector will be connected to the pair of pins and at the same time the short-circuit clip will be pushed by a leg of the female connector to move away from the pair of pins. As a result, the actuation circuit for the squib will get active so that it can actuate the inflator.
When the female connector is to be connected to the pair of pins, the female connector must be inserted in such a way that the direction of holes of the female terminals aligns with the axial direction of the pair of pins. However, as this operation is done manually, the female connector may be inserted in such a way that the direction of holes of the female terminals is oblique to the axial direction of the pair of pins. Such insertion is called oblique insertion. If this occurs, the female connector will force the pins to deform. If such deformation occurs, it will be necessary to make the deformed pins straight or replace the entire inflator with a new one. In either case, it will result in a higher cost.
The present invention was made in view of the above-mentioned points, and one object of the present invention is to prevent forced deformation of pins due to oblique insertion of the female connector and, in turn, reduce costs by providing a shunt with a fitting hole into which the female connector fits and keeping high the elevation of the annular wall of this fitting hole.
To accomplish the above-mentioned objective, the present invention is a shunt, which fits into a cylindrical socket being concavely formed in an external face of a housing of an inflator and short-circuits a pair of pins of a squib, said pair of pins rising at the center of the socket from the bottom to a point near to the opening, said shunt comprises an annular wall having a fitting hole into which pins enter from the bottom side at the center thereof and into which the female connector fits from the top side, and a short-circuit piece, which is provided on said annular wall, will contact both the pair of pins when the shunt is fitted into the socket, and will be pushed to move away from the pins when the female connector is fitted into the fitting hole, the height of said annular wall being not less than the sum of the depth of insertion of the female connector into the fitting hole in the axial direction of t he pins when the female connector is inserted obliquely and the height of the pins from the bottom of the socket.
When this shunt is fitted into the socket, the pins of the squib will enter the fitting hole from the bottom side thereof. As the short-circuit piece contacts both the pair of pins to short-circuit them, the squib will not function. When the female connector is fitted into the fitting hole, the short-circuit piece will be pushed by the female connector to move away from the pins, and at the same time the female connector will contact both the pair of pins to make active the actuation circuit of the squib, enabling the actuation of the inflator.
In this case, if the female connector is inserted obliquely, the female connector will strike on the annular wall and halt. As the depth of insertion of the female connector into the fitting hole in the axial direction of the pins is not more than the length from the top end of the pins to the top of the annular wall, the female connector will not press on the pins. Hence the female connector will not force the pins. Accordingly, the pins will not be deformed, and when the female connector is reinserted properly this time, the female connector will be connected to the pins reliably In this way, the problem can be eliminated and the cost can be lowered.
Similar actions may be obtained by making the housing of the inflator thicker or reducing the height of the pins from the bottom of the socket. However, as the configurations of the inflators and squibs tend to be unified to recommended configurations, the above-mentioned changes will merely invite confusion by increasing the kinds of inflators and squibs. In contrast to them, if the shunt of the present invention is used, the female connector can be prevented from forcing the pins without altering the configurations of the inflator and the squib. Thus the shunt of the present invention is useful.